Chirally tritiated spermidine and spermine will be synthesized by enzymatic decarboxylation of S-adenosyl methionine (SAM) in tritiated water followed by transfer of the propylamine functional group of decarboxylated SAM to 1,4-diaminobutane or spermidine. The Stereochemistry of the plasma amine oxidase catalyzed oxidation of these substrates will provide an important test of our model of the enzyme active site. Experiments involving carboxymethylation of Zn/Co hybrids of yeast alcohol dehydrogenase will be undertaken, in an effort to determine whether the rapid exchange of one of two zinc atoms per subunit by cobalt occurs at a structural vs. catalytic site. Such studies are prerequisites to planned kinetic studies with modified enzymes. The properties of the observed oxidative inactivation of dopamine-Beta-hydroxylase will be pursued in an effort to test our model that dimeric enzyme is an intermediate in enzyme inactivations. Identification of the group(s) undergoing oxidation will be attempted.